[thirdparty/mdadm.git] / ANNOUNCE-2.5

Subject:  ANNOUNCE: mdadm 2.5 - A tool for managing Soft RAID under Linux

I am pleased to announce the availability of
   mdadm version 2.5

It is available at the usual places:
   http://www.cse.unsw.edu.au/~neilb/source/mdadm/
and
   http://www.{countrycode}.kernel.org/pub/linux/utils/raid/mdadm/

mdadm is a tool for creating, managing and monitoring
device arrays using the "md" driver in Linux, also
known as Software RAID arrays.

Release 2.5 adds a host of minor updates and one major update.

The major update involves an "Auto Assemble" function which will,
with certainly limits, scan all available devices for anything that
looks like an md array, and will try to assemble it.
This code should be treated with some caution as it is very new,
and could be revised in future, though hopefully not very much.

The main problem I have always had will auto-assembly is that it
is too easy for it to assemble thing that you don't want assembled,
e.g. if you have moved some devices from a different computer.
To remove this problem, arrays can now be tagged for the computer
that is their home (homehost) and only arrays with the correct
homehost will be auto-assembled.

Feedback on the effectiveness and usefulness of this feature and it's
documentation is encouraged.

Changelog Entries:
    -   Support 'mailfrom' line in mdadm.conf so the From: line in alert
	emails can be explicitly set.
    -   Arrange that SparesMissing (which is similar in import to
	DegradedArray) generates an Email.
    -   Assume "DEVICE partitions" if no DEVICE line is given.
    -   Support new 'offset' layout for raid10.
    -   When creating a bitmap file, choose a chunksize to limit number
	of bitmap chunks to 2 million.  More than this can cause kmalloc
	failure.
    -   New 'CREATE' line in mdadm.conf for defaults such as owner, group,
	mode and auto-flag
    -   --detail checks if array has been started or not and includes that
	in report.
    -   When using --update=uuid on an array with a bitmap, update the
	bitmap's uuid too.
    -   Add a copy of /proc/mdstat to the mail message sent by mdadm
        --monitor.
    -   New flag --no-degraded to avoid starting arrays if there are
	fewer devices available than last time the array was started.
	This is only needed with --scan, as with --scan, that behaviour
	is the default.
    -   Support for 'homehost' concept.  This is a fairly major update.
	It includes a configfile option and a command line option for
	specifying a homehost, records that host in the superblock,
	and reports the homehost where possible.
    -   Support for Auto Assembly.  "mdadm -As" will, if provided with
	the name of a homehost, try to assemble all arrays it can find
	that were created for that homehost.  See man pages for more details.

Development of mdadm is sponsored by
 SUSE Labs, Novell Inc.

NeilBrown  26th May 2006
Commit	Line	Data
41a3b72a NB	1	Subject: ANNOUNCE: mdadm 2.5 - A tool for managing Soft RAID under Linux
	2
	3	I am pleased to announce the availability of
	4	mdadm version 2.5
	5
	6	It is available at the usual places:
	7	http://www.cse.unsw.edu.au/~neilb/source/mdadm/
	8	and
	9	http://www.{countrycode}.kernel.org/pub/linux/utils/raid/mdadm/
	10
	11	mdadm is a tool for creating, managing and monitoring
	12	device arrays using the "md" driver in Linux, also
	13	known as Software RAID arrays.
	14
	15	Release 2.5 adds a host of minor updates and one major update.
	16
	17	The major update involves an "Auto Assemble" function which will,
	18	with certainly limits, scan all available devices for anything that
	19	looks like an md array, and will try to assemble it.
	20	This code should be treated with some caution as it is very new,
	21	and could be revised in future, though hopefully not very much.
	22
	23	The main problem I have always had will auto-assembly is that it
	24	is too easy for it to assemble thing that you don't want assembled,
	25	e.g. if you have moved some devices from a different computer.
	26	To remove this problem, arrays can now be tagged for the computer
	27	that is their home (homehost) and only arrays with the correct
	28	homehost will be auto-assembled.
	29
	30	Feedback on the effectiveness and usefulness of this feature and it's
	31	documentation is encouraged.
	32
	33	Changelog Entries:
	34	- Support 'mailfrom' line in mdadm.conf so the From: line in alert
	35	emails can be explicitly set.
	36	- Arrange that SparesMissing (which is similar in import to
	37	DegradedArray) generates an Email.
	38	- Assume "DEVICE partitions" if no DEVICE line is given.
	39	- Support new 'offset' layout for raid10.
	40	- When creating a bitmap file, choose a chunksize to limit number
	41	of bitmap chunks to 2 million. More than this can cause kmalloc
	42	failure.
	43	- New 'CREATE' line in mdadm.conf for defaults such as owner, group,
	44	mode and auto-flag
	45	- --detail checks if array has been started or not and includes that
	46	in report.
	47	- When using --update=uuid on an array with a bitmap, update the
	48	bitmap's uuid too.
	49	- Add a copy of /proc/mdstat to the mail message sent by mdadm
	50	--monitor.
	51	- New flag --no-degraded to avoid starting arrays if there are
	52	fewer devices available than last time the array was started.
	53	This is only needed with --scan, as with --scan, that behaviour
	54	is the default.
	55	- Support for 'homehost' concept. This is a fairly major update.
	56	It includes a configfile option and a command line option for
	57	specifying a homehost, records that host in the superblock,
	58	and reports the homehost where possible.
	59	- Support for Auto Assembly. "mdadm -As" will, if provided with
	60	the name of a homehost, try to assemble all arrays it can find
	61	that were created for that homehost. See man pages for more details.
	62
	63	Development of mdadm is sponsored by
	64	SUSE Labs, Novell Inc.
65
66	NeilBrown 26th May 2006
67